At present, an electronic cigarette includes a suction nozzle for smoking. The suction nozzle may be an independent part, one end of an atomizer or the whole electronic cigarette. When users use the electronic cigarette, they can smoke with the suction nozzle after a switch of the electronic cigarette is turned on. The user can also directly smoke with the suction nozzle to generate smoking air flow in the electronic cigarette. In this situation, the electronic cigarette can sense the smoking air flow by an air flow sensor, and generate smoke in response to the smoking air flow. After the electronic cigarette is smoked, it can be putted into a cigarette box for the next use.
Because the electronic cigarette has no mark for indicating whether it has been used or not, it is difficult to judge whether the electronic cigarette has been used or not. When many users use a number of electronic cigarettes received in the same cigarette box, one of the electronic cigarettes may be shared by different users, which is unhygienic and may transmit disease. Moreover, even if the cigarette box is a special one, it is difficult to judge whether the electronic cigarettes received in the cigarette box has been used or not.